Quotation sur Édouyot 5:10

And if he must tell him something essential about the other, he should not linger with him in this. For if not so, he will certainly come to lashon hara, as with flash powder, which smells of fire, it being impossible not to ignite the flame [of lashon hara] thereby. And if he began to speak with Reuven about Shimon, not knowing that Reuven hates him and in the course of his conversation he comes to sense that he hates him and that [continuing to talk] would lead to lashon hara — then, if he has no way of leaving him, he should divert the talk to some other matter. Similarly, if he starts talking to someone and feels that when he concludes, he will have been trapped into lashon hara or the like, he should gird his soul to battle his yetzer, stop in the middle, and change the topic, just as, if in the middle of a meal, he were told that he was eating forbidden food, he would certainly stop eating immediately and spit out even what was in his mouth (as written in Ya'aroth D'vash.) And even if he would sometimes come to shame because of this, Chazal have said (Eduyoth 7b): "It is better that a man be called a fool all his life and not be an evildoer for one moment before the L-rd." And Ramban has already written in Sha'ar HaGmul that one moment in Gehinnom is worse than all the suffering of Iyyov all of his days. And it is known that a person would rather be shamed than endure terrible suffering.